<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<title>指定节点操作</title>
<script type="text/javascript">
    function init()
      {
           var element = document.getElementById("js");//找到<li id="js">的元素
           element.style.fontWeight = "bold";//将文本加粗
           var lis = document.getElementsByTagName("li");//找到所有li元素
           lis[0].style.fontSize = "24px";//将第一个li元素的字体设为24px
       }
 </script>
 </head>
  <body onload="init()">
  	<ul>
  		<li id="html">HTML</li>
  		<li id="css">CSS</li>
  		<li id="js">JavaScript</li>
  		<li id="div">DIV</li>
  	</ul>
  </body>
 </html>